There is also the multiple-endpoints principle to think about. The likelihood of this particular set of galaxies forming a ring is very low. The chance of some set of galaxies among all the billions in the sky doing this is much higher. Then we notice and cherry-pick only the one interesting data point, we never notice all the mundane ones.

It's always difficult to tell if a popular-science article is really describing something unusual or if it's using selective perception to create the illusion of one. (I have no idea in this case.)